Recently, demands are increasing for automation and higher performances of machine tools. In order to realize automation, automatic changer apparatuses are proposed such as an automatic tool changer (ATC) which automatically changes tools, and an automatic palette changer (APC) which automatically changes a palette on which a workpiece is mounted. In addition, peripheral apparatuses such as a workpiece supply apparatus such as a loader and a bar feeder are also widely known. In order to realize higher performance, an in-machine measurement and an intelligent system using sensors is also employed.
Further, in order to automate or improve performance of machine tools, in some cases, use of a robot is proposed. For example, JP 2010-36285 A discloses a technique in which a robot provided outside of the machine tool is used, to execute attachment and detachment of the workpiece to and from the machine tool. JP 2010-64158 A discloses a technique in which an articulated robot which travels on a gantry rail attached on an upper part of the machine tool is provided, and the transport of the workpiece or the like among a plurality of machine tools is executed by the articulated robot. JP H5-301141 A and JP H5-301142 A disclose a transporting tool of a workpiece which transports the workpiece by an open/close operation of a grip unit. The transporting tool has an arm shape, and is attached to a body function box. The body function box is also provided at a right side of a spindle head which supports a spindle. The transporting tool can pivot about an axis approximately orthogonal to a long axis of the spindle. The transporting tool can change, by the pivoting movement, between a state in which the arm is approximately horizontal and a state in which the arm is approximately vertical.
However, in the techniques of JP 2010-36285 A and JP 2010-64158 A, the robot is provided outside of the machining chamber. Because of this, when it is desired to access the workpiece and the tool in the machining chamber with the robot, the size of the robot must be increased. A large-size robot, however, not only results in increase in cost and size, but also results in interference with other members, as well as complexity of control due to an increase in the number of joints. In the techniques of JP H5-301141 A and JP H5-301142 A, the robot is provided near the tool spindle. However, the robots of JP H5-301141 A and JP H5-301142 A can only rotate around one axis, and can only transport the workpiece along a predefined route. In other words, with the robots of JP H5-301141 A and JP H5-301142 A, the tool or the workpiece being machined cannot be accessed, and usages of the robot are significantly limited.
An advantage of the present disclosure lies in the provision of a machine tool having a robot which can access a tool and a workpiece, while avoiding an increase in size.